Chromium-containing azo dyestuffs



United- States Patent 2,868,776 CHROMIUMQCONTAINING AZO DYESTUFFS HansRuckstuhl, 'Basel, Switzerland, assignor to Sandoz A. G.,-Basel,Switzerland, a Swiss firm No Drawing. Application May 9, 1957 Serial N0.658,017

Claims priority, application Switzerland May 26, 1955 6 Claims. (cl.260-147 a The present application is a continuation-in-part of copendingapplication Ser. No. 581,326, filed April 30, 1956 (which has beenabandoned since the filing of the present application), and relates tochromium-containing azo dyestuffs which are useful as dyestuffs forW001, silk and synthetic polyamide fibers (e. g. nylon, Perlon(registered trademark)), for pigmenting plastics and lacquers, and fordope-dyeing man-made fibers spun from organic solvents (e. g. celluloseacetate, polyacrylonitrile fibers, polyester fibers).

More particularly the inventon relates to a group of chromium-containingazo dyestuffs which before being chromed correspond to the generalformula SO -B 1/ wherein an stands for hydroxy or methoxy, y stands forchlorineor methyl, and R represents the radical of primary butyl or amylamines containing two hydroxy groups, or of secondarylower alkylamines'carrying one hydroxy group in each alkyl group.

The process for their preparation consists in coupling 1 mol of thediazo compound of an aminobenzene of the general formula 2,868,776Patented Jan. 13, 1 959 2 hydroxy)-ethyl]-amide,-di-[(2-hydroxy)-propyl]-amide and -di-[ (3"-hydroxy) -propyl] -amide.

The coupling of the diazo compounds of the l-hydroxyor1-methoxy-2-amino-6-nitro benzenes of general Formula II with thepyrazolones of general Formula III is carried out advantageously in aweakly alkaline to alkaline medium. The monoazo compounds so formed areseparated from the coupling mass by means of salt and then filtered off.

The conversion of the monoazo compounds into their chromium complexcompound is conducted advantageously in aqueous solution orin an organicmedium, for example formamide, or in the concentrated aqueous solutionof an alkaline salt of a low-molecular aliphatic monocarboxylic acid. Itis advantageous to employ a quantity of chromium-yielding agentcontaining less than two but at least, one chromium atom to twomolecules 7 of the monoazo compound.

' be made if desired.

The new chromium-containing azo dyestuffs possess outstandingneutralaffinity for wool;.most of them dye this fiber from neutral dyebaths andsilk from weakly acid dyebaths in full bluish red shades of very goodfastness to acids, milling, washing and perspiration as well as of anexcellent light fastness. In addition theypossess excellent migrationproperties. They are also suitable for' dyeing leather and areparticularly valuable for the dyeing of man-made nitrogenous fibers suchas synthetic polyamide fibers (e. g. nylon, Perlon (registeredtrademark)). Their good solubility in polar solvents such as acetone,dimethylformamide and tetrahydrofuran permits the new dyestuflfs to beused for dyeing man-made fibers spun from organic solvents (e. g.cellulose acetate, polyacrylonitrile fibers, polyester fibers) and forpigmenting plastics and lacquers.

The following examples illustrate the invention without limiting itsscope. All parts and percentages specified therein are by weight;temperatures are given in degrees centigrade.

EXAMPLE 1 18.9 partsof 1-hydroxy-2-amino-4-chloro-6-nitrobenzene aredissolved in 200 parts of water with 14 parts of a 30% sodium hydroxidesolution. 6.9 parts of sodium nitrite are added to the solution, whichis then run into 30 parts of hydrochloric acid' 30% and ice at 0-5. Theresulting diazo suspension is made weakly alkaline with sodium carbonateand sodium bicarbonate is then added. A sodium hydroxide alkalinesolution of- 34.1 parts of 1-phenyl-3-methyl-5-pyrazolone-3-sulfonicaciddi-[(2"-hydroxy)-ethyl]-amide and 200 parts of water is drop-fedslowly into the suspension. The monoazo dyestufl thus formed iscompletely precipitated; it is filtered off, washed and dried. It is abrown-black powder whichv dissolves in concentrated sulfuric acid withan orange coloration and in dilute sodium hydroidde solution with a redcoloration. It dyes wool by the singlebath chroming process in fastbluish red shades.

The monoazo compound is" converted into the chromifs erous dyestufi byheating with 25 parts .of. sodium acetate. and 40 parts of ammoniumchromic sulfate in 300 parts of formamide for a period of 8 hours at 95.After being allowed to cool to -25 the reaction mixture is poured into700 parts of water; the chromium complex compound is separated by theaddition of 50 parts of sodium chloride and filtered off. The filtercake is entered into 600 parts of water and 45 parts of a sodiumhydroxide solution at room temperature. After brief stirring, 90 partsof sodium chloride are added to'the mass; the precipitated chromiferousazo dyestulf is then filtered off and dried. -It corresponds, in themetal-free state, to the formula 1 Cm-om-on It is soluble in coldacetone, to 100 g. per liter, giving a bluish red solution, and can beused for dyeing cellulose acetate in the dope.

' EXAMPLE 2 The diazo suspension obtained by diazotizing 18.9 parts of1-hydroxy-2-amino-4-chloro-6-nitrobenzene as described in Example 1 ismade weakly alkaline with sodium carbonate and sodium bicarbonate isthen added. A sodium hydroxide alkaline solution of 36.9 parts of 1-phenyl-3-methyl-5-pyrazolone-3'-sulfonic acid-di-(2"-hydroxy)-propyl]amide and 200 parts of water is dropped slowly intothe suspension. The monoazo dyestuif thus formed is completelyprecipitated; it is filtered off, washed and dried. It is a brown-blackpowder which dissolves in concentrated sulfuric acid with an orangecoloration and in dilute sodium hydroxide solution with a redcoloration. It dyes wool by the single-bath chroming process in fastbluish red shades.

The monoazo compound is converted into' the chromiferous dyestuff byheating with 25 parts of sodium acetate and parts of potassium chromicsulfate in 300 parts of formamide for a period of 8 hours at 95 Afterbeing allowed to cool to 2025, the reaction mixture is poured into 700parts of water; the chromium complex compound is separated by theaddition of parts of sodium chloride and filtered off. The'filter cakeis entered into 600 parts of water and 45 parts of a 30% sodiumhydroxide solution at room temperature. After brief stirring, 90 partsof sodium chloride'are added to the mass; the precipitated chromiferousazo dyestuff is then filtered off and dried. It corresponds, in themetal-free state, to the formula OHrCHOH OHa It is a brown-red powderwhich dissolves in concentrated sulfuric acid-With an orange-redcoloration and in water with a bluish red coloration. It dyes wool, silkand synthetic polyamide fibers from neutral to Weakly acid dyebaths infull bluish red shades of excellent fastness to milling, washing andlight. The new dyestufi is also highly soluble in acetone and can beused for dyeing cellulose acetate in the mass.

4.- EXAMPLE 3 16.8 parts of1-hydroxy-2-amino-4-methyl-6 nitrobenzene arediazotized as described in Example 1. The resulting diazo suspension ismade weakly alkaline with sodium carbonate and sodium bicarbonate isthen added. A sodium hydroxide alkaline solution of 34.1 parts of1-phenyl-3-methyl-5-pyraZolone-3-sulfonic acid-(1",1-dimethylol)-ethylamide and 200 parts of water is dropfed slowly into thesuspension. The monoazo dyestuff thus formed is completely precipitated;it is filtered off, washed and dried. It is a brown-black powder whichdissolves in concentrated sulfuric acid with an orange coloration and indilute sodium hydroxide solution with a red coloration. It dyes wool bythe single-bath chroming process in fast bluish red shades.

The monoazo compound is converted into the chromiferous dyestulf byheating with 25 parts of sodium acetate in 300 parts of formamide for aperiod of 8 hours at 95. After being allowed to cool to 20-25, thereaction mixture is poured into 700 parts of water; the chromium complexcompound is separated by the addition of 50 parts of sodium chloride andfiltered off. The filter cake is entered into 600 parts'of water and 45parts of'a 30% sodium hydroxide solution at room. temperature. Afterbrief stirring, parts of sodium chloride are added to the mass; theprecipitated chromiferous azo dyestutf is thenfiltered ofi and dried. Itcorresponds, in the metalfree state, to the formula It is a brown-redpowder which dissolves in concentrated sulfuric acid with an orange-redcoloration and in water with a bluish red coloration. It dyes wool, silkand synthetic polyam-ide fibers from neutral to weakly acid dyebaths infull bluish red shades of excellent fastness to milling, washing andlight. The new dyestufi is also highly soluble in acetone and can beused for dyeing cellulose acetate in the mass.

Further chromium-containing azo dyestuffs can be obtained by treatingwith a chromium-yielding agent a monoazo dyestulf corresponding to thegeneral Formula I. In the following table they are characterized by thesymbols x, y and R, and by the shades of the dyeings on wool.

Table Ex (slhades ofrttlile em so a No. x J y R=Radlcal 01-.- e hroiulumcomplex dyestufis'on wool .4 hydroxychlorine.l,l-dllrlnethylolpropylbluish-red.

am e. H d methyl 0 Do. 6 do-.- chlorine- 1,1-dimethylolethylamlne.- Do.7 do. ---do dt-[(3-hydr0xy)-propyl]- Do.

amine. 8 .--do...-- methyL- --do Do. 9 .do..... ...do.....di-[(2i-hydroxy)-propy1]- D0.

am n 1O .do... ---do-.-.- dl-[( 2-hydroxy)-ethyl]- Do. 11 methoxy do dibD 12.11:: do.-.. firlor'fiii IIIIIdQIIIIIIIIIIIIIIIIII D8: 13......do...;. ..-do-...; VN-(2-hydroxy)-ethyl-N-(2'- Do.

hydroxy)-propyla me- 14--- hydroxy. --do--... d Do. 15 o.-..-; 3 Do;

The following are the formulae of representative dyestuffs, given innon-'mejtallized form of'the foregoing examples.

1 part of anhydrous sodium sulfate and 0.2 part of thechromium-containing azo dyestuff obtainable according to Example 2 aredissolved in 500 parts of water. parts of pre-wetted wool are enteredinto the dyebath, at 30, and the bath is then heated to 100 in thecourse of minutes. The temperature is maintained at 100 for 60 minutes.In the course of the dyeing process, 0.2 part of concentrated aceticacid is added, a little at a time. Upon completion of the dyeing, thewool--which is dyed in bluish-red--is removed from the bath, rinsed withwater and dried.

Synthetic polyamide fibers are dyed in an identical manner; this is alsotrue of silk, except that in this case a somewhat lower temperature-forexample, a temperature of 95 -is employed.

EXAMPLE 17 100 parts of cellulose acetate with a splittable acetic acidcontent of 54-55% are added to 300 parts of solvent (e. g. a mixture of275 parts of acetone and 25 parts of methanol). The mass is stirred andallowed to swell overnight.

On the following day 1 part of the chromiferous azo dyestutf obtainedaccording to Example 1 is dissolved in 60 parts of the same solvent.This solution is added to the cellulose acetate solution and the wholestirred until 60 parts of solvent have evaporated.

After the cellulose acetate solution has been filtered through cottonfabric and a cotton-wool'filter, the further course of the operation tothe formation of the dyed filament is the same as in the production ofundyed cellulose acetate.

Having thusdisclosedthe invention, what is claimed is: l.Chromium-containing azo dyestufis which, in their metal-free state,correspond to the general formula wherein x stands for a member selectedfrom the group consisting of hydroxy and methoxy, y stands for a memberselected from the group consisting of chlorine and methyl, and Rrepresents the radical of a member selected from the class consisting ofprimary butyl and amyl amines containing two hydroxy groups andsecondary lower alkyl amines carrying one hydroxy group in each alkylgroup.

2. The chromium-containing azo dyestuff which, in the metal-free state,corresponds to the formula 3. The chromium-containing azo dyestufiwhich, in the metal-free state, corresponds to the formula 5. Thechromium-containing azo dyestuff 'which, in the metal-free state,corresponds to the formula OzN 6. The chromium-containing azo dyestufiwhich, in

8 References Cited in the file of this patent UNITED STATES PATENTS the2,673,201 Zickendraht et a1. Mar. 23, 1954 5 2,817,655 Schetty t a1.Dec. 24, 1957 I FOREIGN PATENTS 1,090,537 France Oct. 20, 1954

1. CHROMIUM-CONTAINING AZO DYESTUFFS WHICH, IN THEIR METAL-FREE STATE,CORRESPOND TO THE GENERAL FORMULA